Color conversion panel and display device including color conversion panel

ABSTRACT

A color conversion panel includes a first color conversion layer, a second color conversion layer, and a light wavelength conversion layer. The first color conversion layer includes a first semiconductor nanocrystal set for providing red light. The second color conversion layer neighbors the first color conversion layer and includes a second semiconductor nanocrystal set for providing first green light. The light wavelength conversion layer neighbors the second light conversion layer, may provide blue light, and includes a third semiconductor nanocrystal set for providing second green light.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.16/219,845 filed Dec. 13, 2018, which is a continuation of U.S. patentapplication Ser. No. 15/677,471 filed Aug. 15, 2017, which claimspriority to and the benefit of Korean Patent Application No.10-2017-0009160, filed on Jan. 19, 2017, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND (a) Field

The technical field relates to a color conversion panel and a displaydevice.

(b) Description of the Related Art

A display device, e.g., a liquid crystal display device, may include twofield generating electrodes, a liquid crystal layer, a color filter, anda polarization layer overlapping one another. Light leakage may occurat/near the polarization layer and/or the color filter of the displaydevice.

The above information disclosed in this Background section is forenhancement of understanding of the application. This Background sectionmay contain information that does not form the prior art that is alreadyknown in this country to a person of ordinary skill in the art.

SUMMARY

A color conversion panel according to an embodiment includes a firstcolor conversion layer, a second color conversion layer, and a lightwavelength conversion layer positioned on a substrate and representingdifferent colors, wherein the first color conversion layer includes afirst semiconductor nanocrystal emitting red light, the second colorconversion layer includes a second semiconductor nanocrystal emittinggreen light, the light wavelength conversion layer includes a thirdsemiconductor nanocrystal emitting green light, and the green lightemitted from the third semiconductor nanocrystal and blue lighttransmitting through the light wavelength conversion layer are combined.

The second semiconductor nanocrystal and the third semiconductornanocrystal may be the same.

A wavelength of light converted by the second semiconductor nanocrystalto be emitted may be longer than a wavelength of light converted by thethird semiconductor nanocrystal to be emitted.

A content of the third semiconductor nanocrystal may be less than about20 wt % for the entire content of the light wavelength conversion layer.

The wavelength range of the light emitted from the light wavelengthconversion layer may be about 455 nm to about 465 nm.

The light wavelength conversion layer may further include at least oneof a dye and a pigment.

A blue light cutting filter positioned at at least one of between thefirst color conversion layer and the substrate and between the secondcolor conversion layer and the substrate may be further included.

A blue color filter positioned between the light wavelength conversionlayer and the substrate may be further included.

At least one among the first color conversion layer, the second colorconversion layer, and the light wavelength conversion layer may furtherinclude a scattering member.

A display device according to an embodiment includes: a lower panelincluding a thin film transistor; and a color conversion paneloverlapping the lower panel, wherein the color conversion panel includesa first color conversion layer, a second color conversion layer, and alight wavelength conversion layer positioned between a substrate and thelower panel, the first color conversion layer includes a firstsemiconductor nanocrystal emitting red light, the second colorconversion layer includes a second semiconductor nanocrystal emittinggreen light, the light wavelength conversion layer includes a thirdsemiconductor nanocrystal emitting green light, and the green lightemitted from the third semiconductor nanocrystal and blue lighttransmitting through the light wavelength conversion layer are combined.

A light unit positioned at a rear surface of the lower panel may befurther included, and a wavelength of the light emitted from the lightunit may be about 440 nm to about 450 nm.

An embodiment may be related to a color conversion panel. The colorconversion panel may include a first color conversion layer, a secondcolor conversion layer, and a light wavelength conversion layer. Thefirst color conversion layer may include a first semiconductornanocrystal set for providing red light. The second color conversionlayer neighbors the first color conversion layer and may include asecond semiconductor nanocrystal set for providing first green light.The light wavelength conversion layer neighbors the second lightconversion layer, may provide blue light, and may include a thirdsemiconductor nanocrystal set for providing second green light.

Semiconductor nanocrystals of the second semiconductor nanocrystal setmay be identical to semiconductor nanocrystals of the thirdsemiconductor nanocrystal set.

The light wave length conversion layer may receive incident light toproduce output light. A wavelength of the output light may be longerthan a wavelength of the incident light.

The third semiconductor nanocrystal set may be less than 20 wt % of thelight wavelength conversion layer.

The light wave length conversion layer may receive incident light toproduce output light. A wavelength of the incident light may be in arange of 440 nm to 450 nm. A wavelength of the output light may be in arange of 455 nm to 465 nm.

The light wavelength conversion layer may include at least one of a dyeand a pigment.

The color conversion panel may include a blue light cutting filterpositioned between the substrate and at least one of the first colorconversion layer and the second color conversion layer.

The color conversion panel may include a blue color filter positionedbetween the light wavelength conversion layer and the substrate.

At least one of the first color conversion layer, the second colorconversion layer, and the light wavelength conversion layer may includea light scattering member.

An embodiment may be related to a display device. The display device mayinclude the following elements: a transistor panel may include a thinfilm transistor; a first color conversion layer overlapping thetransistor panel and including a first semiconductor nanocrystal set forproviding red light; a second color conversion layer neighboring thefirst color conversion layer and including a second semiconductornanocrystal set for providing first green light; and a light wavelengthconversion layer neighboring the second color conversion layer,configured to provide blue light, and including a third semiconductornanocrystal set for providing second green light.

The display device may include a light unit. The light unit may emitemitted light. The transistor panel may be positioned between the lightunit and the light wavelength conversion layer. A wavelength of theemitted light may be in a range of 440 nm to 450 nm.

Semiconductor nanocrystals of the second semiconductor nanocrystal setmay be identical to semiconductor nanocrystals of the thirdsemiconductor nanocrystal set.

The first green light may have a first green light wavelength. Thesecond green light may have a second green light wavelength. The secondgreen light wavelength is shorter than the first green light wavelength.

The display device may include a light unit. The light unit may emitemitted light. The light wave length conversion layer may receive theemitted light to produce output light. A wavelength of the output lightmay be longer than a wavelength of the emitted light.

The third semiconductor nanocrystal set may be less than 20 wt % of thelight wavelength conversion layer.

The display device may include a light unit. The light unit may emitemitted light. The light wave length conversion layer may receive theemitted light to produce output light. A wavelength of the output lightmay be in a range of 455 nm to 465 nm.

The light wavelength conversion layer may include at least one of a dyeand a pigment.

The display device may include a blue light cutting filter. At least oneof the first color conversion layer and the second color conversionlayer may be positioned between the blue light cutting filter and thetransistor panel.

The display device may include a blue color filter. The light wavelengthconversion layer may be positioned between the blue color filter and thetransistor panel.

At least one of the first color conversion layer, the second colorconversion layer, and the light wavelength conversion layer may includea light scattering member.

The light wavelength conversion layer may include a blue particle set.Each blue particle of the blue particle set may be smaller than eachsemiconductor nanocrystal of the third semiconductor nanocrystal set.

According to embodiments, a color conversion panel and/or a displaydevice may have satisfactory color reproducibility and/or satisfactorylight emission efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a color conversion panel accordingto an embodiment.

FIG. 2 is a cross-sectional view of a color conversion panel accordingto an embodiment.

FIG. 3 is cross-sectional view of a color conversion panel according toan embodiment.

FIG. 4 is a top plan view illustrating a pixel of a display deviceaccording to an embodiment.

FIG. 5 is a cross-sectional view taken along a line V-V of FIG. 4according to an embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments are described with reference to the accompanyingdrawings. As those skilled in the art would realize, the describedembodiments may be modified in various ways.

Although the terms “first”, “second”, etc. may be used herein todescribe various elements, these elements, should not be limited bythese terms. These terms may be used to distinguish one element fromanother element. Thus, a first element discussed below may be termed asecond element without departing from teachings of one or moreembodiments. The description of an element as a “first” element may notrequire or imply the presence of a second element or other elements. Theterms “first”, “second”, etc. may also be used herein to differentiatedifferent categories or sets of elements. For conciseness, the terms“first”, “second”, etc. may represent “first-category (or first-set)”,“second-category (or second-set)”, etc., respectively.

In the drawings and this specification, the same or like constituentelements may be designated by the same reference numerals.

In the drawings, thicknesses of layers and regions may be exaggeratedfor convenience of description.

When a first element (such as a layer, film, region, or substrate) isreferred to as being “on” a second element, the first element can bedirectly on the second element, or one or more intervening elements maybe present between the first element and the second element. Incontrast, when a first element is referred to as being “directly on” asecond element, there are no intended intervening elements (except forenvironmental elements such as air) present between the first elementand the second element. In the specification, the word “on” or “above”may mean positioned on or below an object, and does not necessarily meanpositioned on the upper side of the object based on a gravitationaldirection.

Unless explicitly described to the contrary, the word “comprise” andvariations such as “comprises” or “comprising” may imply the inclusionof stated elements but not exclusion of other elements.

A “semiconductor nanocrystal” may represent a semiconductor nanocrystalset or a set of semiconductor nanocrystals.

FIG. 1 is a cross-sectional view of a color conversion panel accordingto an embodiment.

The color conversion panel includes a light blocking member 321positioned on a substrate 310. A light blocking member 321 may bepositioned at each valley formed between a first color conversion layer330R and a second color conversion layer 330G adjacent in a firstdirection, between a second color conversion layer 330G and a lightwavelength conversion layer 330B adjacent to each other, and between alight wavelength conversion layer 330B and a first color conversionlayer 330R adjacent to each other. The light blocking member 321 maydefine a region where the first color conversion layer 330R, the secondcolor conversion layer 330G, and the light wavelength conversion layer330B are disposed. In an embodiment, the first color conversion layer330R, the second color conversion layer 330G, and the light wavelengthconversion layer 330B are disposed in a matrix/array; portions of alight blocking member 321 may also be positioned between first colorconversion layers 330R adjacent in a second direction perpendicular tothe first direction, between adjacent second color conversion layers330G, and between adjacent light wavelength conversion layers 330B.

A blue light cutting filter 325 is positioned on the substrate 310.

The blue light cutting filter 325 is positioned (or overlaps) a regionemitting red and green and is not positioned in (or does not overlap) aregion emitting blue. The blue light cutting filter 325 may have anopening exposing the region emitting blue. The blue light cutting filter325 may include a portion overlapping the first color conversion layer330R and a portion overlapping the second color conversion layer 330G.

Blue light cutting filters 325 positioned on the substrate 310 may beconnected to each other or may be separated from each other.

The blue light cutting filter 325 transmits light having a wavelengthnot in a blue wavelength band, and blocks light having the bluewavelength band. The blue light cutting filter 325 may include asuitable material to perform the above-described functions. The bluelight cutting filter 325 may be a yellow color filter as an example. Inan embodiment, the blue light cutting filter 325 may be directlyconnected to the first color conversion layer 330R and/or the secondcolor conversion layer 330G. In an embodiment, the blue light cuttingfilter 325 may include a red color filter overlapping the first colorconversion layer 330R and a green color filter overlapping the secondcolor conversion layer 330G. In an embodiment, a blue light cuttingfilter 325 overlapping the first color conversion layer 330R and a bluelight cutting filter 325 overlapping the second color conversion layer330G may be separated from each other.

The color conversion panel according to an embodiment may furtherinclude a buffer layer positioned between the blue light cutting filter325 and the substrate 310.

The first color conversion layer 330R and the second color conversionlayer 330G may be positioned on the blue light cutting filter 325 orcorresponding blue light cutting filters 325, and the light wavelengthconversion layer 330B may be positioned on the substrate 310. Firstcolor conversion layers 330R, second color conversion layers 330G, andlight wavelength conversion layers 330B may be disposed in amatrix/array and may each have an island shape or a stripe shape.

Each of the first color conversion layer 330R, the second colorconversion layer 330G, and the light wavelength conversion layer 330Bmay emit light having a different wavelength from incident light.

The first color conversion layer 330R may be a red color conversionlayer for converting blue light to emit red light. The first colorconversion layer 330R may include a first semiconductor nanocrystal(set) 331R for converting the incident blue light into the red light.The first semiconductor nanocrystal 331R may include at least one of aphosphor (set) and a quantum dot (set).

The first semiconductor nanocrystal 331R may include a red phosphor, andthe red phosphor may contain one of (Ca, Sr, Ba)S, (Ca, Sr, Ba)₂Si₅N₈,CaAlSiN₃, CaMoO₄, and Eu₂Si₅N₈.

The second color conversion layer 330G may be a green color conversionlayer for converting blue light to emit green light. The second colorconversion layer 330G may include a second semiconductor nanocrystal(set) 331G for converting the incident blue light into the green light.The second semiconductor nanocrystal 331G may include at least one of aphosphor set and a quantum dot set.

The second semiconductor nanocrystal 331G may include a green phosphor,and the green phosphor may contain one of yttrium aluminum garnet (YAG),(Ca, Sr, Ba)₂SiO₄, SrGa₂S₄, BAM, α-SiAlON, β-SiAlON, Ca₃Sc2Si₃O₁₂,Tb₃Al₅O₁₂, BaSiO₄, CaAlSiON, and (Sr(1-x)Bax)Si₂O₂N₂. In an embodiment,the x may be any number between 0 and 1.

The light wavelength conversion layer 330B may include a thirdsemiconductor nanocrystal (set) 331B for converting a first portion ofincident blue light into green light. Semiconductor nanocrystals of thethird semiconductor nanocrystal (set) 331B may be substantiallyidentical to semiconductor nanocrystals of the second semiconductornanocrystal (set) 331G. The third semiconductor nanocrystal 331B mayinclude at least one of a green phosphor (set) and a quantum dot (set).The third semiconductor nanocrystal (set) 331B may include fewersemiconductor nanocrystals than the second semiconductor nanocrystal(set) 331G.

The light wavelength conversion layer 330B may emit a second portion ofthe incident blue light with an unchanged first wavelength. The secondportion of the blue light and the green light provided by the thirdsemiconductor nanocrystal (set) 331B may be combined inside or at thelight wavelength conversion layer 330B. As a result, the lightwavelength conversion layer 330B may provide blue light having a secondwavelength unequal to the first wavelength.

The first wavelength of both the incident blue light and the output bluelight may be in a range of about 440 nm to about 450 nm, and thewavelength of the output green light resulted from the conversion of thefirst portion of the incident blue light by the third semiconductornanocrystal 331B may be in a range of about 530 nm to about 540 nm. Theoutput blue light (having the first wavelength) and the output greenlight (resulted from the conversion performed by the third semiconductornanocrystal 331B) are combined such that the light wavelength conversionlayer 330B may emit the output blue light having a wavelength in a rangeof about 455 nm to about 465 nm. The output blue light having a width insuch a wavelength range may have excellent color reproducibility.

The third semiconductor nanocrystal set 331B may be less than about 20wt % of the light wavelength conversion layer 330B. That is, the weightpercent of the third semiconductor nanocrystal set 331B in the lightwavelength conversion layer 330B may be less than about 20 wt %. If theweight percent of the third semiconductor nanocrystal set 331B in thelight wavelength conversion layer 330B is larger than 20 wt %, theoutput light emitted from the light wavelength conversion layer 330B maynot represent blue, or the blue color reproducibility may be reduced.

The light wavelength conversion layer 330B may include at least one of adye (set) and a pigment (set) 335. The dye and/or pigment 335 may be ablue dye and/or a blue pigment, and the dye and/or pigment 335 mayabsorb red light and/or green light and may emit blue light, therebyimproving color reproducibility. The weight percent of the dye and/orpigment 335 in the light wavelength conversion layer 330B may be in arange of about 1 wt % to about 5 wt %.

The first color conversion layer 330R, the second color conversion layer330G, and the light wavelength conversion layer 330B may include quantumdots (instead of or alternative to phosphors) for performing colorconversion. The quantum dots may include one or more of a Group II-VIcompound, a Group III-V compound, a Group IV-VI compound, a Group IVelement, and a Group IV compound.

The Group II-VI compound may include one or more of at least atwo-element compound (such as at least one of CdSe, CdTe, ZnS, ZnSe,ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and MgS), at least a three-elementcompound (such as at least one of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe,ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe,CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, and MgZnS), and at least afour-element compound (such as at least one of HgZnTeS, CdZnSeS,CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, andHgZnSTe). The Group III-V compound may include one or more of at least atwo-element compound (such as at least one of GaN, GaP, GaAs, GaSb, AlN,AlP, AlAs, AlSb, InN, InP, InAs, and InSb), at least a three-elementcompound (such as at least one of GaNP, GaNAs, GaNSb, GaPAs, GaPSb,AlNP, AINAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, and InPSb),and at least a four-element compound (such as at least one of GaAlNAs,GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb,GaAlNP, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb). The Group IV-VIcompound may include one or more of at least a two-element compound(such as at least one of SnS, SnSe, SnTe, PbS, PbSe, and PbTe), at leasta three-element compound (such as at least one of SnSeS, SnSeTe, SnSTe,PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, and SnPbTe), and at least afour-element compound (such as at least one of SnPbSSe, SnPbSeTe, andSnPbSTe). The Group N element may include Si and/or Ge. The Group Ncompound may be/include a two-element compound, such as SiC and/or SiGe.

In an embodiment, the binary compound, the tertiary compound, or thequaternary compound may be particles and may have equal or unequalconcentrations. In an embodiment, a core/shell structure in which somequantum dots enclose some other quantum dots may be implemented. Aninterfacing surface between the core and the shell may have aconcentration gradient in which a concentration of an element decreasescloser to the center of the particle (or quantum dot).

The quantum dots may have a full width at half maximum (FWHM) of alight-emitting wavelength spectrum of about 45 nm or less, preferablyabout 40 rim or less, and more preferably about 30 nm or less; in thisrange, the color purity and/or the color reproducibility may beoptimized. Light emitted through these quantum dots may be emitted inmany/all directions; therefore, the viewing angle may be maximized.

In embodiments, shapes of the quantum dots are not specifically limitedto shapes that are generally used in the related art. In embodiments, aquantum dot may be/include a nanoparticle (having a spherical,pyramidal, multi-arm, or cubic shape), a nanotube, a nanowire, ananofiber, and/or a planar nanoparticle.

At least one of the first color conversion layer 330R, the second colorconversion layer 330G, and the light wavelength conversion layer 330Bmay further include one or more light scattering members 337. Forexample, each of the first color conversion layer 330R, the second colorconversion layer 330G, and the light wavelength conversion layer 330Bmay include a light scattering member 337. In an embodiment, the lightwavelength conversion layer 330B includes a scattering member 337, andthe first color conversion layer 330R and the second color conversionlayer 330G may include no light scattering members. The contents and/orstructures of the light scattering members 337 included respectively inthe first color conversion layer 330R, the second color conversion layer330G, and the light wavelength conversion layer 330B may be differentfrom each other.

A light scattering member 337 may evenly scatter incident light and mayinclude at least one of TiO₂, ZrO₂, Al₂O₃, In₂O₃, ZnO, SnO₂, Sb₂O₃, andITO.

The first color conversion layer 330R, the second color conversion layer330G, and the light wavelength conversion layer 330B may each include aphotosensitive resin and may be manufactured by at least aphotolithography process. In an embodiment, the first color conversionlayer 330R, the second color conversion layer 330G, and the lightwavelength conversion layer 330B may be manufactured through at least aprinting process and may include materials different from aphotosensitive resin.

FIG. 2 is a cross-sectional view of a color conversion panel accordingto an embodiment. FIG. 3 is a cross-sectional view of a color conversionpanel according to an embodiment. The color conversion panels describedwith reference to FIG. 2 and FIG. 3 may include structures and/orfeatures that are identical to or analogous to structures and/orfeatures described with reference to FIG. 1.

Referring to FIG. 2, a blue color filter 325B is positioned between asubstrate 310 and a light wavelength conversion layer 330B. The bluecolor filter 325B may reduce external light reflection and/or mayimprove color reproducibility.

The blue color filter 325B may replace or supplement the dye and/orpigment described with reference to FIG. 1. According to an embodimentillustrated in FIG. 2, the light wavelength conversion layer 330B maynot include a dye or a pigment.

The light wavelength conversion layer 330B may include a thirdsemiconductor nanocrystal 331B for converting incident blue light intogreen light. According to an embodiment, semiconductor nanocrystals ofthe third semiconductor nanocrystal set 331B may be identical tosemiconductor nanocrystals of the second semiconductor nanocrystal set331G. The third semiconductor nanocrystal 331B may include at least oneof the green phosphor and a quantum dot for converting blue light intogreen light.

The light wavelength conversion layer 330B may receive incident bluelight having a first wavelength for providing output blue light having asecond wavelength. The first wavelength may be in a range of about 440nm to about 450 nm, and the second wavelength may in a range of be about455 nm to about 465 nm. The output blue light emitted from the lightwavelength conversion layer 330B may have a longer wavelength than theblue light incident to the light wavelength conversion layer 330B.

The light wavelength conversion layer 330B may emit the output bluelight having the second wavelength by combining a first portion of theincident blue light that is emitted as it is with green light resultedfrom conversion of a second portion of the incident blue light.

In an embodiment, the first wavelength of the incident blue light may bein a range of about 440 nm to about 450 nm, and the wavelength of thegreen light provided by the third semiconductor nanocrystal 331B may bein a range of about 530 nm to about 540 nm. The first portion of theblue light having the first wavelength and the green light provided bythe third semiconductor nanocrystal 331B are combined into the outputblue light having a wavelength in a range of about 455 nm to about 465nm. The output blue light having a wavelength in the wavelength rangemay have excellent color reproducibility.

The weight percent of the third semiconductor nanocrystal 331B in in thelight wavelength conversion layer 330B may be less than about 20 wt %(relative to the entire light wavelength conversion layer 330B). If theweight percent of the third semiconductor nanocrystal 331B is largerthan the 20 wt %, the light emitted from the light wavelength conversionlayer 330B may not represent blue or the blue color reproducibility maybe undesirable.

At least one of the first color conversion layer 330R, the second colorconversion layer 330G, and the light wavelength conversion layer 330Bmay further include one or more light scattering members 337.

Next, referring to FIG. 3, the light wavelength conversion layer 330Bmay include a third semiconductor nanocrystal set 331B for converting afirst portion of incident blue light to emit green light. The thirdsemiconductor nanocrystal 331B may convert blue light having a firstwavelength (in a range of about 440 nm to 450 nm) into green lighthaving a third wavelength (about 480 nm to about 520 nm). The thirdwavelength may be shorter than the wavelength of the light emitted fromthe second semiconductor nanocrystal 331G. That is, the secondsemiconductor nanocrystal 331G and the third semiconductor nanocrystal331B may emit green lights having unequal wavelengths.

The light wavelength conversion layer 330B may emit a second portion ofthe incident blue light with the first wavelength as it is. The lightwavelength conversion layer 330B may emit output blue light having thesecond wavelength by combining the second portion of the incident bluelight and the green light resulted from conversion of the first portionof the incident blue light. In an embodiment, the first wavelength maybe in a range of about 440 nm to about 450 nm, and the wavelength of thegreen light may be in a range of about 480 nm to about 520 nm. Thesecond wavelength may be in a range of about 455 nm to about 465 nm. Theoutput blue light may have excellent color reproducibility.

The weight percent of the third semiconductor nanocrystal 331B may beless than about 20 wt % relative to the entire the light wavelengthconversion layer 330B. If the weight percent of the third semiconductornanocrystal 331B is larger than 20 wt %, the output light may not beblue or the blue color reproducibility may be undesirable.

According to an embodiment, the third semiconductor nanocrystal set 331Bmay be associated with a shorter wavelength than the secondsemiconductor nanocrystal 331G, and the light wavelength conversionlayer 330B may not include any dye, any pigment, or any additional bluecolor filter.

At least one of the first color conversion layer 330R, the second colorconversion layer 330G, and the light wavelength conversion layer 330Bmay further include one or more light scattering members 337.

FIG. 4 is a top plan view illustrating a pixel of a display deviceaccording to an embodiment, and FIG. 5 is a cross-sectional view takenalong a line V-V of FIG. 4. The display device may include a colorconversion panel that has elements, structure, and/or features identicalto or analogous to elements, structure, and/or features of at least oneof the color conversion panel discussed with reference to FIG. 1, thecolor conversion panel discussed with reference to FIG. 2, and the colorconversion panel discussed with reference to FIG. 3.

Referring to FIG. 4 and FIG. 5, the display device includes a light unit500 and a display panel 10 positioned on the light unit 500. The displaypanel 10 includes a lower panel 100 (or transistor panel 100) includinga thin film transistor, a color conversion panel 300 overlapping thelower panel 100, and a liquid crystal layer 3 positioned between thelower panel 100 and the color conversion panel 300.

The light unit 500 may include a light source positioned at a rearsurface of the display panel 10 and generating light and may include alight guide receiving the light and guiding the received light in thedirection of the display panel 10. In an embodiment, the display panel10 is an organic light emitting panel, and the light unit 500 may beomitted.

The light unit 500 may include at least one light emitting diode (LED),which may be a blue light emitting diode (LED). The light source may bean edge type of light unit disposed on at least one lateral surface ofthe light guide (not shown), or a direct type of light unit in which thelight source of the light unit 500 is disposed directly under the lightguide.

The light emitted from the light unit 500 may have a first wavelength,and the first wavelength may be in a range of about 440 nm to about 450nm. The first wavelength corresponds to a relatively short wavelengthrange such that the large excited energy may be provided to the firstsemiconductor nanocrystal 331R and the second semiconductor nanocrystal331G. The first color conversion layer 330R and the second colorconversion layer 330G to which the light is incident may have desirablelight conversion efficiency.

The display panel 10 may include the liquid crystal panel for forming avertical electric field or a horizontal electric field, a plasma displaypanel (PDP), an organic light emitting diode display (OLED), a surfaceconduction electron-emitter display (SED), a field emission display(FED), a vacuum fluorescent display (VFD), or an E-paper. In anembodiment, the display panel 10 may form a vertical electric field.

The lower panel 100 is positioned between the liquid crystal layer 3 andthe light unit 500.

The lower panel 100 includes a first polarization layer 12 positionedbetween a first substrate 110 and the light unit 500. The firstpolarization layer 12 may polarize the light incident to the light unit500.

The first polarization layer 12 may be/include one or more of adeposited-type polarizer, a coating-type polarizer, and a wire gridpolarizer. The first polarization layer 12 may be positioned at onesurface of the first substrate 110 by one or more of various methodssuch as a film type, a coating type, an adhering type, a printing type,etc.

Pixels are disposed in a matrix/array in the first substrate 110. Thefirst substrate 110 is positioned between the first polarization layer12 and the liquid crystal layer 3.

A gate line 121 extending in an x direction and including a gateelectrode 124, a gate insulating layer 140 positioned between the gateline 121 and the liquid crystal layer 3, a semiconductor layer 154positioned between the gate insulating layer 140 and the liquid crystallayer 3, a data line 171 positioned between the semiconductor layer 154and the liquid crystal layer 3, extending in a y direction, andconnected to a source electrode 173 and a drain electrode 175, and apassivation layer 180 positioned between the data line 171 and theliquid crystal layer 3 may be formed between the first substrate 110 andthe liquid crystal layer 3. A pixel electrode 191 is positioned on thepassivation layer 180. The pixel electrode 191 may be physically andelectrically connected to the drain electrode 175 through a contact hole185 included in the passivation layer 180. A first alignment layer 11may be positioned between the pixel electrode 191 and the liquid crystallayer 3.

The semiconductor layer 154 forms a channel layer at a part that is notcovered by the source electrode 173 and the drain electrode 175, and thegate electrode 124, the semiconductor layer 154, the source electrode173, and the drain electrode 175 form one thin film transistor.

The color conversion panel 300 includes a substrate 310 overlapping thelower panel 100. A light blocking member 321 and a blue light cuttingfilter 325 are positioned between the substrate 310 and the liquidcrystal layer 3.

The blue light cutting filter 325 overlaps the region emitting the redand the green, and is positioned on the substrate 310. The blue lightcutting filter 325 may include an opening exposing the region emittingthe blue.

A first color conversion layer 330R and a second color conversion layer330G are respectively positioned between portions of the blue lightcutting filter 325 and the liquid crystal layer 3.

The first color conversion layer 330R may be a red color conversionlayer. The first color conversion layer 330R may include a firstsemiconductor nanocrystal set 331R for converting incident blue lightinto red light.

The second color conversion layer 330G may be a green color conversionlayer. The second color conversion layer 330G may include a secondsemiconductor nanocrystal set 331G for converting incident blue lightinto green light.

The light wavelength conversion layer 330B may be positioned between thesubstrate 310 and the liquid crystal layer 3.

The light wavelength conversion layer 330B may include a thirdsemiconductor nanocrystal set 331B converting a first portion ofincident blue light into green light. According to an embodiment,semiconductor nanocrystals of the third semiconductor nanocrystal 331Bmay be identical to semiconductor nanocrystals of the secondsemiconductor nanocrystal set 331G. The third semiconductor nanocrystalset 331B may include at least one of a green phosphor set and a greenquantum dot set for converting blue light into green light.

The light wavelength conversion layer 330B may further include at a dyeand/or pigment set 335. The dye/pigment set 335 may include a blue dyeand/or a blue pigment for absorbing red light and/or green light to emitblue light, for improving color reproducibility.

At least one of the first color conversion layer 330R, the second colorconversion layer 330G, and the light wavelength conversion layer 330Bmay further include one or more light scattering members 337.

A photo-filter layer 340 may be positioned between the first colorconversion layer 330R, the second color conversion layer 330G, and thelight wavelength conversion layer 330B, and the liquid crystal layer 3.

The photo-filter layer 340 may be a filter for preventing damage toand/or extinction of the phosphor set or the quantum dot set included inthe first color conversion layer 330R, the second color conversion layer330G, and the light wavelength conversion layer 330B in high temperatureprocesses, for transmitting the light of the predetermined wavelength,and/or for reflecting or absorbing light except for the light of thepredetermined wavelength.

The photo-filter layer 340 may include a structure in which inorganicfilms having a high refractive index and inorganic films having a lowrefractive index are alternately stacked at least 10 times and at most20 times. That is, the photo-filter layer 340 may have a structure inwhich layers having different refractive indexes are stacked. In anembodiment, the photo-filter layer may reflect or absorb light of aspecific wavelength. It may transmit and/or reflect light of a specificwavelength using reinforcement interference and/or destructiveinterference between the inorganic films and the inorganic films.

The photo-filter layer 340 may include at least one of TiO₂, SiNx,SiO_(y), TiN, AlN, Al₂O₃, SnO₂, WO₃, and ZrO₂, and for example, may be astructure in which SiNx layers and SiO_(y) layers are alternatelystacked. The x and y in SiN_(x) and SiO_(y) as factors determining achemical composition ratio may be controlled depending on processconditions when forming the layers.

An overcoat layer 360 is positioned between the photo-filter layer 340and the liquid crystal layer 3. The overcoat layer 360 flattens onesurface of the first color conversion layer 330R, the second colorconversion layer 330G, and the light wavelength conversion layer 330Btoward the liquid crystal layer 3.

A second polarization layer 22 is positioned between the overcoat layer360 and the liquid crystal layer 3. The second polarization layer 22 maybe positioned on the flattened surface of the overcoat layer 360.

The second polarization layer 22 may be one or more among the depositedpolarization layer, the coated polarization layer, and the wire gridpolarization layer, and as one example, the second polarization layer 22may include a metal pattern wire polarization layer. The secondpolarization layer 22 may be positioned between the overcoat layer 360and the liquid crystal layer 3 by various methods such as the film type,the coating type, the adhering type, the printing type, etc. In anembodiment, one surface of the overcoat layer 360, on which the secondpolarization layer 22 is formed, is flat such that the secondpolarization layer 22 may be stably formed.

A common electrode 370 is positioned between the second polarizationlayer 22 and the liquid crystal layer 3. Although not shown in thepresent specification, when the second polarization layer 22 is a metalmaterial, an insulating layer (not shown) may be additionally positionedbetween the common electrode 370 and the second polarization layer 22.

The common electrode 370 receiving a common voltage forms an electricfield along with the pixel electrode 191, thereby rearranging aplurality of liquid crystal molecules 31 positioned in the liquidcrystal layer 3.

A second alignment layer 21 is positioned between the common electrode370 and the liquid crystal layer 3. The liquid crystal layer 3 includesa plurality of liquid crystal molecules 31, and a movement of the liquidcrystal molecules 31 is controlled by the electric field between thepixel electrode 191 and the common electrode 370. Transmittance of lightreceived from the light unit 500 is controlled depending on the movementdegree of the liquid crystal molecules 31, for displaying an image.Next, the light conversion efficiency and the color reproducibility ofthe color conversion panel according to an experimental example and acomparative example are described.

First, as an experimental example, when using light unit having awavelength of about 445 nm, it is confirmed that the light conversionefficiency of the second semiconductor nanocrystal is about 130%.However, in a case of the comparative example using the light unithaving a wavelength of about 458 nm, it may be confirmed that the lightconversion efficiency of the second semiconductor nanocrystal is about100%. That is, in the case of the experimental example according to anembodiment, it may be confirmed that the light conversion efficiency isincreased by about 30%.

Next, the color reproducibility of the red color conversion layer isdescribed with reference to Table 1. It is represented that the colorreproducibility is better when an X coordinate of the red light iscloser to 0.68 and a Y coordinate is closer to 0.32 based on DCI colorcoordinates.

Experimental Example 1 represents color coordinates of the red colorconversion layer including the light unit having a wavelength of about445 nm, and Experimental Example 2 represents red color coordinates fora case including the light unit having a wavelength of about 445 nm andincluding the blue light cutting filter. Comparative Example 1represents red color coordinates for a case of providing the light unithaving a wavelength of about 458 nm, and Comparative Example 2represents red color coordinates for a case of providing the light unithaving a wavelength of about 458 nm and providing the blue light cuttingfilter.

TABLE 1 X coordinate Y coordinate Experimental Example 1 0.610 0.336Experimental Example 2 0.638 0.332 Comparative Example 1 0.531 0.348Comparative Example 2 0.586 0.340

Referring to Table 1, in the case of Experimental Examples 1 and 2compared with Comparative Examples 1 and 2, it is confirmed that the Xcoordinate is closer to 0.68 and the Y coordinate is closer to 0.32.Accordingly, it is confirmed that the color reproducibility of the redlight emitted from the red color conversion layer is improved bychanging the wavelength of the light unit.

Additionally, as a result of an experimental example in which the lightunit has a 445 nm wavelength and the light wavelength conversion layerincludes the second semiconductor nanocrystal or the third semiconductornanocrystal, it is confirmed that a DCI matching ratio is about 99.4%.However, in a comparative example in which the light unit has a 445 nmwavelength, but the light wavelength conversion layer does not includethe semiconductor nanocrystal, it is confirmed that the DCI matchingratio is about 97.7%. This is because the color reproducibility of theblue light according to the comparative example deteriorates in thelight wavelength conversion layer region emitting the blue light.

In summary, in the region emitting the red and the region emitting thegreen, the display device according to an embodiment may provide theblue light having the short wavelength to improve the light conversionefficiency and to improve the color reproducibility. However, when theblue light simply transmits through the light wavelength conversionlayer, the color reproducibility of the blue may be reduced. Anembodiment may emit the output blue light having a longer wavelengththan the incident blue light wavelength. Accordingly, as the colorreproducibility is improved in the region emitting the blue, the displaydevice may have improved color reproducibility.

While example embodiments have been described, practical embodiments arenot limited to the disclosed embodiment, but are intended to covervarious modifications and equivalent arrangements within the spirit andscope of the appended claims.

What is claimed is:
 1. A color conversion panel comprising: a firstcolor conversion layer including a first particle set configured toconvert incident blue light to emit red light; a second color conversionlayer neighboring the first color conversion layer and including asecond particle set configured to convert the incident blue light toemit green light; and a light wavelength conversion layer neighboringthe second color conversion layer and configured to emit the green lightand transmit the incident blue light.